Lateral imbalance of an aircraft, originated by minor, unavoidable and tolerable structural shape deviations occurring in the production process, e.g. asymmetric wing twist, is a well known phenomenon in aircraft design. Such a lateral imbalance may lead to a constant offset rolling moment that needs to be compensated during flight permanently. There are several means known such as a constant deflection of ailerons, flap rigging and attaching wedges to a bottom flap surface at a trailing edge.
U.S. Pat. No. 4,542,868 discloses a wedge-shaped structural component for attachment to the bottom surface of an aircraft wing profile near or along the trailing edge of the aircraft wing. Said wedge-shaped structural component is intended to improve the lift coefficient and to reduce the drag during cruising speeds.
U.S. Pat. No. 6,382,561 B1 discloses a trailing edge wedge for an aircraft wing for attachment to the bottom surface of only one of two wings of an aircraft directly next to and along the trailing edge of the wing and preferably parallel thereto. This trailing edge wedge is designed in a way to compensate any asymmetric aircraft characteristics that are due to the sum of all unavoidable structural tolerances by locally increasing the lift coefficient of the respective wing.
A rather simple way to compensate asymmetric aircraft characteristics is to slightly deflect an aileron on one wing permanently in order to generate a compensating rolling moment. The deflection leads to a distinct drag penalty and therefore is to be avoided.